Bitter, Sweet, and Salty

Salty and sweet are distinct tastes which our taste buds are usually able to detect. However, if you add salt to some foods, they do not taste salty, but become sweeter tasting. This is because salt is not just a taste, it is also a taste enhancer.

Bitter and sweet cancel each other out to some degree. Think of adding sugar to naturally bitter coffee and you get the idea. It cancels/masks the bitterness. Some people add a bit of salt to the grounds before making coffee, for the same reason.

Pineapples are sweet, but also have some bitterness to them. If you neutralize the bitterness, it should taste sweeter. Adding salt can do this. When salt mixes with the pineapple, the salt splits up into sodium and chloride ions. The chloride is tasteless and our tongues ignore it. The sodium bonds with the acids in the pineapple and forms a similarly tasteless salt, but the bitterness effectively disappears. What remains is the sweetness of the pineapple. Add a little bit of salt to your fresh pineapple and enjoy the enhanced sweetness. It also works with watermelon, oranges, grapefruit, dark chocolate and other foods that are both bitter and sweet. Perhaps this is one reason why it is said that bacon is the food that makes other foods taste better. My father always salted apples before eating and usually paired with extra sharp cheddar cheese.

Adding salt works less well with canned or other processed fruits as many are already artificially sweetened.

Salt

Saltiness is one of the five primary basic tastes the human tongue can detect. Those five tastes being: salt, bitter, sweet, sour, and umami (it is from glutamic acid, which is found in many foods, particularly some meats, and is the basis of the flavor enhancer monosodium glutamate, also known as MSG).

Extra salt has other effects, beside simply making things more salty it helps certain molecules in foods more easily release into the air, thus helping the aroma of the food, which is important in perception of taste.

Adding a bit of salt will also decrease the bitter taste perception in food, which is why it is often sprinkled on grapefruit.

Salt does not suppress sweet or sour flavors as with bitter flavors, but balances out the taste by making the perceived flavor of sugary candies or lemons, less one dimensional.